Means for launching lifeboats



A. P. scHAf 2,

MEANS FOR LAUNCHING LIFEBOATS Filed Nov 18, 1936 2 sheets-sheet 1 Dec.27, 1938. A P, SCHAT 2,141,452

MEANS FOR LAUNCHING LIFEBOATS Filed Nov. 18, 1936 2 Sheets-Sheet 2Patented Dec. 27, 1938 2,141,452 MEANS FOR LAUNCHING LIFEBOATS AnePieter Schat, Utrecht, Netherlands Application November 18, 1936, SerialNo. 111,502

Claims.

This invention relates to ships davits and has for its object to providesimple and ready means for launching boats therefrom.

According to the invention, the lower end of 5 each davit arm ispivoted, by a horizontal and longitudinal pivot axis, to a carriageadapted to travel down an outwardly sloping track, the davit arm and thecarriage being further interconnected by a member, which is hinged tothe davit arm intermediate the foot and the head thereof and also hingedto the carriage a suitable distance inwardly of said pivot axis, so asto prevent the davit arm from swinging outwards beyond a predeterminedangular distance.

Said member may, for instance, be a chain, or a rod pivoted to thecarriage and having a pin and slot connection with the davit arm, orvice versa. Preferably, however, it is used in the form of a togglejoint lever, the one link of which is hinged to the davit arm and theother to the carriage in such a manner that said lever will besubstantially stretched when the davit arm is fully swung out. With thisconstruction, the toggle joint may be engaged by a guideway so formedthat movement of the joint along the same during the outward movement ofthe carriage forces the davit arm to swing out.

Three convenient embodiments of the invention are described withreference to the drawings erewith, in which:

Fig. l is a view in elevation of the first embodiment as seen from oneend of the boat, the latter being shown in its inboard position,

Fig. 2 is a view in elevation of part of said 35 embodiment as seen fromthe inboard side of the boat, and

Figs. 3 and 4 are views in elevation of the second and of the thirdembodiment, respectively, both as seen from one end of the boat.

It is to be understood that in Figs. 1, 3 and 4 the carriage with thedavit arm and the element interconnecting both for arresting the saidarm when fully swung out are shown both in the extreme inboard and inthe extreme outboard positions. Like parts are designated by the samenumerals throughout the figures.

In Figs. 1 and 2, the suitably curved davit arm designated by 5. Thesame is pivoted, by a horizontal pivot axis 5, to a carriage 1 arrangedto run on an outwardly inclined track composed of two channels 8, 8 withtheir open sides facing each other. Said carriage l is provided at itsinboard end with two'rollers 9, 9 and at its outboard end with tworollers ill, ill, all adapted to run upon the top faces of the bottomflanges of the channels 8, 8.

The rollers 553, it are mounted upon the pivot 6, about which the davitarm 5 is adapted to perform the required lufling movement, and therollers 9, 9 are mounted on a common pin H, which also serves as thepivot of a link l2, the end of which is hinged as at it to a second linkIt pivoted as at id to the central portion of the davit arm. 5. Thelinks H, it thus form the toggle joint lever referred to hereinbefore.

The boat H6 in its stowed position as shown in Fig. l is suspended from,a pulley block ll pivoted to the respective end of the boat and havingpivoted thereto a slip-hook it, which is engaged by a hook-shaped memberE9 of the davit head. In said position the boat is also supported bychecks 2t, 2t secured to the davit arm 5.

The fall 22, by means of which said end of the boat can be lowered,starts from a winch drum 23, which is secured to a deck 2 t, runs over apulley 25 loosely mounted on the pin H, and engages the inboard side ofa pulley 26 rotatable about a stud pin 2! secured to the central part ofthe davit arm 5 whence it is led around a pulley 28 rotatable about apin 29 supported by the davit head. From the pulley 28, it passes to andaround the sheave it? of the pulley block i? and is reeved around asecond pulley 3! on the pin 29, whence it is led to a cleat 32 securedto the davit arm 5.

In its stowed position, the boat is secured by a gripe 33, one end ofwhich is fixed to a bolt of the davit arm 5, the other end beingconnected through a sliphook 35 and a short chain 35 to the tail M of acatch hook 38, which is pivoted as at 39 to the track 8, 8 and adaptedto engage over the pivot pin ll of the roller t, 5 to retain thecarriage l inboard.

It will be understood that the other end of the boat is suspended in asimilar manner from the head of a second davit arm, and that its fallmay be led back to a second drum of the winch 23, by means of which,therefore, both falls can be payed out and hauled in.

To launch the boat it, the gripe 33 is cast off by means of theslip-hook 35, whereby the catch hook 33 can be released. The carriage lis then retained solely by its fall 22. On paying out the fall, thedavit arm 5 will first swing out about its pivot 6 until it is arrestedby the toggle link lever ii, it, it and assumes the position 5', whereinthe eye it still engages the hook it, and thereupon the carriage l,together with the davit arm ii and the boat it, goes down its track 8, sby gravity until reaching the extreme outboard end of the track, whereit is arrested by a stop 43. This extreme outboard position of the davitarm 5 is indicated by 5".

In this position, a man in the boat releases the slip-hook is from thehook-shaped member 59, whereby the weight of the boat is taken up by thefall 22, so that further paying out of the fall simply lowers the boat.

To get the boat inboard, the fall is wound in, raising the boat untilthe slip-hook l8 engages the member l9, so that the boat is againdirectly suspended from the davit head, after which the carriage I isdrawn up the track 8, 8 and the davit arm swung inboard. At the extremeinner end ofthe travel of" the carriage I, the catch hook 38 isre-engaged and the gripe 33 replaced.

When the vessel has a considerable list, the boat on the low side, whenfreely suspended from its falls with the davit arms swung out. at thelower ends of the tracks l8, l8, wouldbe spaced an excessive distancefrom, and thus be liable to be smashed against the ships side.

the carriage 1 to be provided with means whereby it can be locked in anyposition between the higher and the lower end of its track. This can beaccomplished, for instance, by mounting the rollers l0, H] on a spindlehaving right and left handed screw thread, so that by turning saidspindle in the proper direction the said rollers can be moved laterallyaway from each other and forced against the webs of the channels 8, thuspreventing the carriage from going down.

In Fig, 3, the davit arm 5 is provided near its foot with a pivoted toe4i having rollers 62 adapted to run upon the top faces of the topflanges of the channels 8, 8. As long as the rollers 42 engage the saidtopfaces, thedavit arm 5 is prevented from swinging about its pivot axis6, since the toe 4! is prevented, by a suitable stop, to turn inclockwise direction. ther details of the installation shown in Fig. 3are substantially similar to those shown in Fig. 1, so that they neednot be described, Thus, when. the stowed boat 16 is to be launched and.the gripe 33 is cast off, paying out of the fall 22 will cause thecarriage 1 to go down with the davit 5 in its original position relativethereto. Only if, near the lower end of the track, the toe 4| disengagesthe channels 8, 8 and to turn in anti-clockwise direction relative tothe davit arm, the latter is free to swing out. This position of thedavit is indicated by 5, whereas 5" shows the extreme outboard position.7

In the modification shown in Fig. 4, the pivot l3 of the toggle joint isguided by a suitably curved slot 43 in a rigid plate 44 secured on topof the track 8, 8; the curvature of said slot being so that during thedownward motion of the cariage I along its track the link i l of thetoggle link lever gradually turns the davit arm 5 out ward relative tothe carriage, and that the davit arm is fully swung out to assume itsposition 5" when the carriage l engages the stop 40 at th lower end ofthe track 8, 8.

What I claim is: r

1. In an installation for handling a lifeboat on board a vessel, thecombination with a track arranged athwartships on the vessel and slopingdown towards the water, of a carriage adapted to run on the track, adavit arm connected with its foot to the carriage so as to be capable ofluffing movement relative thereto, and a linkage comprising pivotallyconnected members hinged to the davit arm intermediate the foot and thehead thereof and also hinged to the carriage a suitable distanceinwardly of said connection so as to prevent the 'davit' arm fromlufiing outward beyond a predetermined angular distance.

2. In an installation for handling a lifeboat V on board a vessel, thecombination with a track arranged athwartships on the vessel and slopingdown towards the water, of a carriage adapted to run on the track, adavit arm having its foot In order to be able to reduce this distance tothe very minimum under all circumstances, it is desirable for The fur- 7axis arranged longitudinally of the vessel, and a toggle jointcomprising connected links, an intermediate pivotal connection betweenthe links of the toggle, said toggle being hinged to the davit armintermediate the foot and the head thereof and also hinged to thecarriage a suitable distance inwardly of said axis so as to prevent thedavit arm from swinging about said axis outward beyond a predeterminedangular distance and means to move the intermediate pivotal connectionof the toggle relatively to the hinged connections of the latter withthe davit arm and the carriage. i

3. In an installation for handling a lifeboat on board a vessel, thecombination with a track arranged athwartships on the vessel and slopingdown towards the water, 'of a carriage adapted to run on the track, adavit arm having its foot hinged to the carriage by a horizontal andlongitudinal pivot axis, a toggle joint comprising connected links, anintermediate pivotal connection between the links of. the toggle, saidtoggle being hinged to the davit arm intermediate the foot and the headthereof and also hinged to the carriage a suitable distance inwardly ofsaid axisso as to prevent the davit arm fromswinging about said axisoutward beyond a predetermined angular distance', and a member havingformed therein a guideway in non-parallel relation with the track andengaging the intermediate pivotal, connection of the toggle joint so asto force the davit arm to turn outward relative to the carriage when thecarriage moves down on its track.

4. In an installation for handling a lifeboat on board a vessel, thecombination with a track 7 arranged athwartships on the vessel andsloping down towards the water, of a carriage adapted to run on saidtrack, a davit arm'conneoted with its foot to the carriage so as to becapable of lufing movement relative thereto and provided with a toeadapted when the davit arm assumes its inwardly swung position to run onthe track so as to prevent the davit from lufling but to allow of suchluffing movement when disengaging. the track near the lower end thereof,and a member hinged to the davit arm intermediate the foot and the headthereof and also hinged to the carriage a suitable distance inwardly ofsaid connection so as to prevent the davit arm from lufiing outwardbeyond a predetermined angular distance. r

5. In an installation for handling a lifeboat on board a vessel, thecombination with a track arranged athwartships on the vessel and slopingtowards the water, of a carriage adapted to run on the track, a davitarm having its foot pivoted to the carriage by a. horizontal pivotalaxis arranged longitudinally of the vessel, a toggle jointcomprisingconnected links, an intermediate pivotal connection betweenthe links

